Danielius Studio · iOS

Pink Crumb

Hum a note. FFT finds the pitch. On-device.

Hold the capture button and hum for two to four seconds. Pink Crumb taps the microphone through Apple's AVAudioEngine, runs an FFT on the buffer via the Accelerate framework (vDSP), finds the dominant frequency in Hz, and maps it to the nearest musical note label such as C4 or A#3. The captured clip, the measured Hz, and the labeled note are saved as one dated crumb. By December, every day's pitch becomes a scrollable year you can revisit.

How it works

Open Pink Crumb once a day. Tap the capture button on Home.
Hum into the microphone for two to four seconds.
The app runs an FFT on the buffer and shows you the measured frequency in Hz plus the closest musical note.
Save the crumb. The short audio clip stays on your device.
Pin the Lock Screen or Home Screen widget to see today's note label at a glance.

What Pink Crumb is, and is not

Pink Crumb is a personal-artifact app: a daily hum-to-pitch journal. The note label is an estimate from a single dominant-frequency bin, not a calibrated chromatic tuner. It is not a song-recognition service, not a vocal-training coach, not a music-theory tutor, and not a substitute for professional audio software. It is a quiet daily ritual that turns a few seconds of humming into a labeled, listenable memory.

What stays on your device

No accounts, no email, no signup.
No analytics, no third-party SDKs.
FFT pitch detection runs entirely on-device through the Accelerate framework. Audio never leaves your phone.
Crumbs (the short m4a clip, the measured Hz, the labeled note) are stored on-device with SwiftData.
The only network calls Pink Crumb makes are to Apple's StoreKit when you choose to subscribe or buy Lifetime.

Pricing

Three crumb entries are free, lifetime. Pro unlocks unlimited crumbs, the scrollable year of pitch labels, and the Lock Screen widget:

Pro Monthly: $4/month, with a 14-day free intro on the first subscription.
Pro Annual: $25/year.
Pro Lifetime: $59 one-time.

All purchases are handled by Apple and managed under your Apple ID. Pro is Family-Shareable through Apple's standard Family Sharing.

Support

Questions, bugs, or a feature request? support@danielius.studio. Replies typically within a day or two.

To restore a purchase on a new device, open Pink Crumb, tap the settings icon, open the paywall, and tap Restore Purchases. Apple will re-verify your Apple ID's entitlements.

To cancel an auto-renewing subscription, open the Settings app on iPhone, tap your name at the top, then Subscriptions, then Pink Crumb Pro.